1. Field of the Invention
The present invention relates to the field of working and transporting objects in ultraclean atmospheres. It more particularly relates to the microelectronics industry.
2. Description of Related Art
In certain industries, such as microelectronics, some operations such as the preparation of silicon wafers must be carried out in a substantially impurity or dust-free atmosphere, i.e. in so-called white rooms. This is obtained by ventilating the rooms with air which has been filtered by absolute filters, i.e. those stopping even the finest dust.
It is also possible to transport or store silicon wafers in containers within which there is such an ultraclean atmosphere without the atmosphere of the rooms in which the containers are located being ultraclean. Therefore, these containers must be tight with respect to the dust in the said rooms.
Moreover, it is often necessary to transfer one or more silicon wafers between individual containers, e.g. from a storage container to a transportation container. The opening of the doors of the containers and the passage of the object from one container to the other cause problems of sealing with respect to the ultraclean atmosphere. Part of the problem could be solved by coupling together the two ultraclean containers prior to the opening of the two doors. However, like all the outer faces of the containers, the door has previously been in contact with the atmosphere prevailing in the room. Therefore, the coupling together of the two containers involves confining within the ultraclean volume defined by the interior of the two containers of the door and its polluted outer face.
The aim of the invention is to obviate this disadvantage by proposing a system of coupling together the two containers and opening the container doors without polluting the two containers by the outer face of the two doors.